From: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: 'GNU C Library' <libc-alpha@sourceware.org>
Subject: Re: [PATCH v2] string: Fix OOB read on generic strncmp
Date: Thu, 23 Feb 2023 19:10:52 +0000 [thread overview]
Message-ID: <PAWPR08MB8982C0B56AC7D9160E5107E083AB9@PAWPR08MB8982.eurprd08.prod.outlook.com> (raw)
Hi Adhemerval,
What kind of readahead are you trying to test/fix here? It's not clear from the
patch... So with strcmp you can safely call strlen on either input, and similarly I
believe you can call strnlen on both inputs of strncmp without getting a crash.
That means it is possible to read ahead as long as you never read past a zero
byte or past the given size.
If you couldn't read even a single byte past the first mismatch it would be hard
to create efficient implementations, especially with wide vectors...
Cheers,
Wilco
next reply other threads:[~2023-02-23 19:11 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-23 19:10 Wilco Dijkstra [this message]
-- strict thread matches above, loose matches on Subject: below --
2023-02-24 12:24 Wilco Dijkstra
2023-02-24 12:34 ` Adhemerval Zanella Netto
2023-02-24 12:43 ` Szabolcs Nagy
2023-02-24 12:57 ` Adhemerval Zanella Netto
2023-02-22 16:31 Adhemerval Zanella
2023-02-22 17:21 ` Szabolcs Nagy
2023-02-23 18:15 ` Adhemerval Zanella Netto
2023-02-24 10:19 ` Szabolcs Nagy
2023-02-24 10:58 ` Florian Weimer
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